package cn.lkx.commonutils;

import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jws;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import org.springframework.util.StringUtils;

import javax.servlet.http.HttpServletRequest;
import java.util.Date;

/**
 *
 */
public class JwtUtils {
    public static final long EXPIRE = 1000 * 60 * 60 * 24;  //token过期时间
    public static final String APP_SECRET = "ukc8BDbRigUDaY6pZFfWus2jZWLPHO"; //密钥
    //生成token字符串方法
    public static String getJwtToken(String id, String nickname){
        String JwtToken = Jwts.builder()
                //设置头信息
                .setHeaderParam("typ", "JWT")
                .setHeaderParam("alg", "HS256")
                //设置过期时间
                .setSubject("MyMoocEdu-user")
                .setIssuedAt(new Date())
                .setExpiration(new Date(System.currentTimeMillis() + EXPIRE))
                //设置主体部分，存储用户信息
                .claim("id", id)  //用户id
                .claim("nickname", nickname)  //用户昵称
                //签名Hash，生成密钥规则
                .signWith(SignatureAlgorithm.HS256, APP_SECRET)
                .compact();
        return JwtToken;
    }
        /**
        * 判断token是否存在与有效
        * @param jwtToken
        * @return
        */
        public static boolean checkToken(String jwtToken) {
            if(StringUtils.isEmpty(jwtToken)) return false;
            try {
                Jwts.parser().setSigningKey(APP_SECRET).parseClaimsJws(jwtToken);
            } catch (Exception e) {
                e.printStackTrace();
                return false;
            }
            return true;
        }

        /**
        * 判断token是否存在与有效
        * @param request
        * @return
        */
        public static boolean checkToken(HttpServletRequest request) {
            try {
                String jwtToken = request.getHeader("token");
                if(StringUtils.isEmpty(jwtToken)) return false;
                Jwts.parser().setSigningKey(APP_SECRET).parseClaimsJws(jwtToken);
            } catch (Exception e) {
                e.printStackTrace();
                return false;
            }
            return true;
        }

        /**
        * 根据token字符串 获取会员id
        * @param request
        * @return
        */
        public static String getMemberIdByJwtToken(HttpServletRequest request) {
            String jwtToken = request.getHeader("token");
            if(StringUtils.isEmpty(jwtToken)) return "";
            Jws<Claims> claimsJws = Jwts.parser().setSigningKey(APP_SECRET).parseClaimsJws(jwtToken);
            Claims claims = claimsJws.getBody();
            return (String)claims.get("id");
        }
}
